Pressurized garments



June 20, 1961 T. P. O'HALLORAN PRESSURIZED GARMENTS Filed Nov. 19. 1959 FIG. I.

FIGA.

Inventor 7;: 0 mm a RrmcKmIM Aitorney United States Patent 2,989,324 PRESSURIZED GARMENTS Thomas Patrick OHalloran, 'Camberley, England, as-

signor to Minister of Supply in Her Majestys Government of the United Kingdom of Great Britaln and Northern Ireland, London, England Filed Nov. 19, 1959, Ser. No. 854,203 1 Claim. (Cl. 285-235) This invention relates to pressurized garments, by which term is meant a garment made of flexible inextensible material comprising a fluid tight layer or layers constrtuting a pressure tight chamber or chambers whereby the whole or part of the body of the person wearing the garment may have external pressure applied to it by inflation of the chamber. Such pressurized garments are used to enable aviators to exist at a high altitude where ambient pressures are very low.

One problem inherent in the construction of such garments is that because of the inextensible but flexible nature of the material of which they are made, the tubular portions enclosing the arms, legs and trunk become stifll when inflated due to the pressure occurring between the wall of the garment and the body of -the wearer and exert considerable resistance to the wearer bending at the 'oints. The present invention provides for such garments an improved joint or elbow portion comprising four annular elements of flexible material, all having a single radial slit from inner to outer circumferential edge and being extended so that the circumferential edges run longitudinally of the joint and being connected to one another by seams running in this direction, the seams being located approximately in relation to a cross section of the joint at 0, 90, 180 and 270 stations, the seam at 0 and that at 180 each connecting outer longer edges of different pairs of annuli and the seams at 90 and at 270 each connecting the inner shorter edges of the annuli brought adjacent as a result of the 0 and 180 seams.

By this construction the 0 and 180 seams are effectively equal in length to the outer circumferential measurement of an annulus and the 90 and 270 seams are equivalent to the inner circumferential measurement of an annulus, whilst the circumferential measurement of the tubular joint is equal to four times the radial dimension of an annulus whereby the wall of the joint in the immediate area of the 90 and 270 seam will fit snugly over the arm of the wearer, in contrast to the Wall in the area of the 0 and 180 seam which will fit loosely to permit easy movement.

The joint is connected to adjacent portions of the garment by seams along the edges originally bounding the radial slits.

By arranging the joint so that the shorter seams joining the inner circumferential edges of the annuli pass through the desired axis of bending there will be little resistance to bending when the garment and joint is inflated because the material of the annuli will be strained mainly and almost entirely along transverse circumferential lines running from the shorter seams to the longer seams, that is, along radial lines of the original annuli and, at the same time, because the construction provides ample surplus material which is unstrained longitudinally, the pressure changes at the joint and hence resistance to bending due to this cause are slight.

One example of a joint according to the invention will now be described with reference to the accompanying diagrammatic drawings in which FIG. 1 shows two rubberized fabric hollow sleeve elements to be connected by means of the joint.

FIG. 2 shows four rubberized fabric annular elements which will be connected to form the joint.

FIG. 3 shows a preliminary step in joining the annuli to form the joint.

FIG. 4 shows the completed joint connected to the two sleeve portions to form the elbow.

The hollow cylindrical sleeve elements 10 and 11 are sections of a flexible pressurized garment enclosing portions of one limb of the wearer. These sleeve elements are connected one to the other by means of a joint 16 constructed of annular elements 12, 13, 14 and 15. These annular elements are radially slit as at S. The dimensions of the cylindrical and annular elements are arranged so that the radial length of the edges of all the slits is equal to one quarter the circumference of the cylinder (plus the usual seaming allowances). In FIGURE 2 the important features of the six elements are lettered to aid in understanding the mode of their assembly in constituting the joint as shown in FIGURES 3 and 4.

Referring to FIGURES 2 and 3 the four annular elements are first seamed (by means of conventional seaming process not a part of this invention) together in pairs by seaming the extended inner circumferential edge AC of the annular element 12 to corresponding the edge EG of the annular element 13; and seaming the extended edge KI of the annular element 14 to edge MO of the annular element 15.

Referring to FIGURES 3 and 4 the two-element members thus formed are then joined to form a tube by seaming the extended circumferential edge DB to edge LI and edge FH to edge NP and the joint then completed by seaming the composite edge CD LK MN FE to the edge of the cylindrical elements 10 and the composite edge 151B JI OP HG to the edge of the other cylindrical element With the construction of sleeve joint described and with the sleeve inflated the arm of the wearer may be bent about an axis passing through the seams ECAG and KMIO with no serious resistance to bending.

The joint may be improved by reinforcing the seams such as ECAG and KMIO with tension or restraining members such as cords or chains as it is these seams where maximum tensile strength without extension is required.

It is to be noted that if the seams such as ECAG and KMIO and the attached restraining members where fitted are approximately diametrically opposed the pressure within the joint is approximately uniform no matter what angle of bend is adopted, the surplus material in seams such as LDJB and FNHP remaining slack in the longi tudinal direction while these seams remain a constant dimension from the other two, this dimension being the original radial dimension of one of the annular elements.

The joint has the advantage that it may be bent through about a virtual point axis without giving excessive resistance whereas the known convoluted type of joint construction permits only limited bending movement.

It will be appreciated that the joint can be applied to any part of a pressurized garment.

I claim:

A flexible joint portion for an inflatable garment comprising four annular elements of material, all having a single radial slit from inner to outer edge and being extended so that the circumferential edges run longitudinally of the joint and being connected to one another by seams 3 4 running in this direction, the seams being located approxi- References Cited in the file of this patent mately in relation to a cross section of the joint at 0, UNITED STATES PATENTS 90, 180 and 270 stations, the seam at 0 and that at 180 each connecting outer edges of difierent pairs of 1,985,427 Richardson 251 1934 annuli and the seams at 90 and at 270 each connecting 5 the inner edges of the annuli brought adjacent as a result FOREIGN PATENTS of the 0 and 180 seams. 540,955 Germany Jan. 7, 1932 

